Not applicable.
The present invention relates generally to agricultural equipment and more specifically to a coulter overload protection apparatus for use with a planter assembly.
An exemplary agricultural planter assembly may includes support wheels centrally mounted to a long (e.g., 40 feet) implement bar with a tongue member extending centrally from the support wheels to a hitch on a tractor or some other type of prime mover and a plurality (e.g., sixteen) of separate coulter/fertilizer units and corresponding row units. Hereinafter, unless indicated otherwise and in the interest of simplifying this explanation, an exemplary planter assembly including a forty foot long implement bar and sixteen row units and corresponding coulter/fertilizer units will be assumed.
Each coulter/fertilizer unit is typically mounted to a front end of a corresponding row unit and includes a coulter or cutting knife member that cuts a fertilizer trench in soil there below and a fertilizer dispensing tube that delivers fertilizer into the fertilizer trench. The row units are mounted to the implement bar in an equi-spaced configuration. An exemplary row unit includes a seed bin, a dispenser and some type of soil agitator (e.g., a coulter or knife assembly). During operation, the agitators are forced into the ground and form seed trenches.
Each bin is mounted above a corresponding dispenser and feeds seed to the dispensers via gravity. The dispensers open behind corresponding agitators and drop seed into the seed trenches. The coulter/fertilizer units and corresponding row units are typically offset somewhat (e.g.,. 2 inches) so that the seed and fertilizer trenches are separated so that the fertilizer does not xe2x80x9cburnxe2x80x9d the seed as well known in the art. Once the seed sprouts, new plant roots make there way into the fertilizer trenches and growth is enhanced.
Typically the implement bar is moveable between an upright position where the ground engaging components of the row units and coulter/fertilizer units are raised above the ground for transport and a ground engaging position where the units can be activated to trench and fertilize and seed, respectively. Here the motive force for moving the implement bar between the upright and ground engaging positions may be either hydraulic or mechanical.
While a long implement bar and corresponding large number of row units and coulter/fertilizer units is advantageous during a planting operation (e.g., more row units translate into less time to perform a planting operation), long implement bars are difficult to accommodate during machine transport between fields, about a farmers property and during storage. To accommodate optimal transport and operating planter configurations, the industry has developed several different folding or pivoting implement bar configurations. One such pivoting configuration (hereinafter xe2x80x9cthe pivoting assemblyxe2x80x9d) is described in U.S. patent application Ser. No. 10/062,612 which is entitled xe2x80x9cPlanter Hitch Apparatusxe2x80x9d was filed on Jan. 31, 2002 and which is incorporated herein, in its entirety, by reference. The pivoting assembly includes an implement bar and other components mounted to a mainframe assembly.
Hereinafter, unless indicated otherwise, when the implement bar is referenced, it will be assumed that the reference includes the implement bar and all other attached assembly components including the row units, the coulter/fertilizer units, etc. and when the implement bar weight is referenced it will be assumed that the implement bar weight reference corresponds to the combined weight of the implement bar and all attached components. In addition, unless indicated otherwise, when the mainframe is referenced, it will be assumed that the reference includes the mainframe and all other attached assembly components including the implement bar, the row units, the coulter/fertilizer units, etc. and when the mainframe weight is referenced it will be assumed that the mainframe weight reference corresponds to the combined weight of the mainframe and all attached components.
The pivoting assembly includes a carrier assembly having a carrier frame and a platform. The platform is mounted to a top surface of the carrier frame and the carrier frame has a width that should be relatively stable during operation and yet is limited to a dimension suitable for transport purposes. For instance, the width dimension may be 10 to 12 feet for a planter assembly including a 40 foot implement bar. Support wheels are mounted to the underside of the carrier frame along a single axis and proximate a rear edge of the carrier platform with at least one wheel proximate each end of the carrier frame width dimension so that the wheels provide stable support for the carrier frame and carrier platform there above. The mainframe is pivotally mounted to a rear side corner of a carrier platform so that the mainframe and implement bar attached thereto can be positioned perpendicular to the transport direction during operation and parallel to the transport direction during transport.
A roller or wheel assembly is spaced apart from the pivot and mounted to the underside of the mainframe to ease the conversion process between the transport and operating positions and to provide support to the mainframe and attached implement bar.
In addition, to support the implement bar when in the operating position, lateral support wheels are mounted to the distal ends of the implement bar that can be extended to engage the ground there below or can be retracted during conversion between the implement bar positions and during transport.
Whenever a wheel supported planter assembly is going to be attached to a tractor hitch for transport and operation, ideally the planter assembly is configured such that the implement assembly load is relatively balanced across the support wheels but has some positive hitching weight so that the assembly remains stable during transport. Here, as the phrase implies, positive hitch weight is caused by configuration weight disposed between the support wheels and a tractor hitch which tends to bear down on the hitch. Where positive hitch weight is to great some tractors may have difficulty moving a hitched planter assembly. Similarly, as the phrase implies, negative hitch weight is caused by configuration weight disposed on a side of the support wheels opposite the hitch and tends to tip the assembly tongue upward away from the hitch.
In the case of the pivoting assembly described above, it has been determined that, to best balance the implement assembly load across the support wheels in both the transport and operating positions, the implement bar and row units should be mounted such that, when the implement bar is in the operating and upright position (i.e., extends perpendicular to the transport direction with the row units in the upright position), the bar (and attached row units) is generally behind the support wheels. With the row units and bar mounted in this manner, when the implement bar is upright and in the operating position, the weight of the implement bar and the hitch and carrier platform together provide a stabilizing positive weight that is somewhat balanced in front of and behind the support wheels, the possibility of negative weight is minimal, the implement bar weight is essentially balanced on either lateral side of the wheels and is supported generally evenly across the pivot point and the roller assembly. In addition, when the implement bar is in the transport position (and hence is necessarily upright), the weight of the implement bar and attached components is greater in front than it is behind the support wheel axis, the overall positive weight is stable and yet not to great, the implement bar is positioned above the carrier platform and the implement bar weight is essentially evenly laterally distributed above the platform.
Unfortunately, when the implement bar and row units are optimally juxtaposed behind the support wheels, the wheels make it impossible to attach coulter/fertilizer units to the front ends of some of the row units. For instance, assume that a planter assembly includes 16 separate row units with six central units directly behind the platform and support wheels and five lateral units to either side of the six central units. In this case, while coulter/fertilizer units can be attached to the front ends of the ten lateral units (i.e., five lateral units on either side of the central units), the wheels are in the space required to attach the coulter/fertilizer units to the six central row units.
Therefore, it would be advantageous to have a planter assembly that includes a separate coulter/fertilizer unit positioned in front of each row unit where the assembly is pivotal to facilitate conversion between operating and transport positions.
It has been recognized that a coulter/fertilizer assembly can be attached to the underside of the carrier frame in front of the support wheels where the assembly includes a separate coulter/fertilizer unit for and aligned with each of the central row units. To this end, the coulter/fertilizer assembly in at least one embodiment includes a coulter bar mounted to the underside of the carrier frame that extends along the width of the carrier frame in front of the support wheels. A separate coulter/fertilizer units is mounted to the coulter bar in front of each of the central row units with the same fertilizer-seeding offset described above. Additional coulter/fertilizer units are mounted to the front ends of the lateral row units on either side of the central units. The coulter/fertilizer units mounted to the coulter bar will be referred to hereinafter as central coulter units and the coulter/fertilizer units mounted to the front ends of the lateral row units will be referred to hereinafter as lateral coulter/fertilizer units
Typically, like the implement bar, the coulter bar will be constructed such that it can be moved between a ground engaging position wherein the coulter/fertilizer units facilitate fertilization and an upright position wherein the coulter/fertilizer units are stored above ground for transport. While the coulter/fertilizer assembly may be constructed such that the coulter bar is manually moveable between the upright and ground engaging positions, in some embodiments the coulter bar may be pivotally mounted to the carrier frame and linked to a hydraulic cylinder. In some embodiments, when the cylinder is extended the coulter bar is moved to the upright position and when the cylinder is retracted the coulter bar is driven toward the ground engaging position.
One problem with coulter/fertilizer units is that the coulters can become damaged if too much force is applied thereto. For instance, if a coulter contacts a rock while being pulled through a field, the slicing edge of the coulter may be damaged or, in some cases, even destroyed.
In the case of the lateral coulter/fertilizer units (i.e., in the present example, to the five row units on either side of the central row units and proximate the ends of the implement bar), the implement bar has been known to flex somewhat such that, when a coulter contacts a large rock or the like, the implement bar absorbs some of the impacting force and the coulter is forced over the rock thereby minimizing coulter damage.
Unfortunately, because the coulter bar is relatively short, the coulter bar does not appreciably flex and therefore cannot absorb much force that is applied to the central coulter unit coulters. Thus, the central coulter unit coulters that are linked to the relatively inflexible coulter bar are far more susceptible to damage than the coulters linked to the flexible implement bar.
To protect the central coulter units, at least one embodiment of the invention includes an overload protection mechanism that, when the force on the central coulter units exceeds a preset threshold force, reduces the force on the central coulter units by allowing the coulter bar to pivot toward the upright or transport position. Here, the threshold force level is selected to be less than the a force level that will likely cause coulter damage.
Consistent with the above discussion, one embodiment of the invention includes a coulter apparatus for use with a planter assembly constructed to move in a transport direction where the planter assembly includes support wheels mounted to the underside of a carrier frame, the apparatus comprising a coulter bar pivotally mounted to the underside of the carrier frame on a side of the support wheels facing the transport direction for pivotal movement between a transport position and a functional position, a plurality of coulter/fertilizer units mounted to the coulter bar such that, when the coulter bar is in the functional position, the coulter/fertilizer units are in a lower ground engaging position and when the coulter bar is in the transport position, the coulter/fertilizer units are in an upright ground clearance position, a hydraulic cylinder mounted between the coulter bar and the carrier frame for driving the coulter bar between the transport and functional positions, the carrier frame, cylinder and coulter bar forming a linkage path and an overload protector linked within the linkage path such that a draft force applied to the coulter bar in a direction opposite the transport direction causes a secondary force on the protector, when the secondary force exceeds a threshold force level, the protector de-linking the linkage path thereby reducing the draft force.
In some embodiments the cylinder includes a rod end and a base end and the protector includes a relief valve plumbed into at least one of the rod and base ends, the relief valve opening when the secondary pressure thereon exceeds the threshold pressure level. More specifically, the planter assembly may further include a hydraulic fluid reservoir and the relief valve is linked to the reservoir and, wherein, when the cylinder is retracted, the path between the relief valve and the reservoir is unobstructed. Here, the relief valve may be plumbed between the rod and base ends.
In some embodiments the cylinder is mounted to the carrier frame on a side of the coulter bar opposite the support wheels. The relief valve may be plumed into the rod end of the cylinder. In fact, the relief valve may be plumbed between the rod and the base ends.
The planter assembly may include first and second intermediate hydraulic ports and a pilot-operated check valve linked between the second intermediate port and the rod end to allow flow from the second intermediate port to the rod end and only allow flow from the rod end to the second intermediate port when hydraulic pressure is applied at the first intermediate port. Some embodiments may also further include a coulter valve linked between the first intermediate port and the base end.
The cylinder may be a first cylinder and the planter assembly may further include an implement bar pivotally mounted to the carrier frame and a second hydraulic cylinder linked between the carrier frame and the implement bar for driving the implement bar between a transport position and a functional position. Here, the second cylinder may be plumbed between the first intermediate port and the first cylinder rod end. More specifically, the second cylinder rod end may be plumbed to the first cylinder rod end.
Some embodiments further include first and second lift valves linking the first and second inlet ports to the first and second intermediate ports, respectively. The planter assembly may include a hydraulic source and the first and second inlet ports may be linked to the source.
The planter assembly may further include a hydraulic fluid reservoir and the relief valve may be linked to the reservoir and, when the cylinder is retracted, the path between the relief valve and the reservoir may be unobstructed. The planter assembly may still further include row units mounted to the implement bar and the row units may include at least one row unit aligned with each coulter/fertilizer unit mounted to the coulter bar.
The invention further includes an apparatus for use with an agricultural assembly constructed to move in a transport direction where the assembly includes support wheels mounted to the underside of a carrier frame, the apparatus comprising at least one ground engaging member linked to the underside of the carrier frame for pivotal movement between an upright ground clearance transport position and a lower ground engaging functional position, a hydraulic cylinder including a rod end and a base end linked between the engaging member and the carrier frame for moving the engaging member between the transport and functional positions and a relief valve plumbed into at least one of the rod and base ends, the relief valve opening when a pressure thereon exceeds a threshold pressure level thereby allowing the engaging member to move toward the transport position.
In some embodiments the assembly further includes a hydraulic fluid reservoir and the relief valve is linked to the reservoir and, wherein, when the engaging member is in the functional position, the path between the relief valve and the reservoir is unobstructed. In some embodiments the one engaging member is mounted to the carrier frame on a side of the support wheels facing the transport direction. In still more specific embodiments the relief valve is plumbed between the rod and base ends.
The assembly may include first and second intermediate hydraulic ports and a pilot-operated check valve linked between the second intermediate port and the rod end to allow flow through the second intermediate port to the rod end and only allow flow from the rod end through the second intermediate port when hydraulic pressure is applied at the first intermediate port.
The engaging member may include a coulter bar and a plurality of coulter/fertilizer units mounted thereto.